1. Field of the Invention
The present invention relates to an apparatus and method for controlling cooling of a linear motor, and more particularly to an apparatus and method for controlling cooling of a linear motor in which as a heat generated from linear motor is sensed, the linear motor is cooled by using a cooling fan or an air nozzle by sensing heat generated from the linear motor.
2. Description of the Background Art
Generally, as shown in FIG. 1, a linear motor includes a stator 10 and a mover 20. Referring to the stator 10, a plurality of permanent magnets 12 are installed at predetermined intervals at both inner sides of a xe2x80x98Uxe2x80x99-type frame 11. The mover 20 includes a coil block 22 at the lower portion of a flat-type frame 21. The coil block 22 is formed in a manner that a plurality of coils 22a are arranged at predetermined intervals and molded.
As a driving power (not shown) is supplied to the coil block 22, current flows to the coil block 22, so that a magnetic field is generated between the plurality of permanent magnets 12 disposed at the inner side of the stator 10 and the coil block 22, according to which thrust is generated to move the mover 20.
In case where the driving power is supplied for a long time, the coil 22a is overloaded, so that much heat is generated. In this case, the flat type frame 21 of the mover 20 is thermally deformed, or the heat generated from the coil is conducted to the xe2x80x98Uxe2x80x99-type frame 11 of the stator 10, causing a thermal deformation of the stator 10.
In the case that the stator or the mover is thermally deformed, a linear motor adopted for use to a high speed and precision mechanic field would be malfunctioned. In case that the linear motor makes an error, various kinds of machines adopting such a defective linear motor would be damaged critically.
Therefore, an object of the present invention is to provide an apparatus and method for controlling cooling of a linear motor in which, upon sensing a temperature corresponding to a heat generated from a linear motor, in case that the sensed temperature is higher than a pre-set reference temperature, a cooling fan installed at a stator and an air valve for opening and closing air to be supplied to the mover are controlled to cool the linear motor.
Another object of the present invention is to provide an apparatus and method for controlling cooling of a linear motor in which, upon comparing a temperature sensed in a linear motor with a pre-set reference temperature, in case that the sensed temperature is lower than the pre-set reference temperature, a cooling fan for cooling the linear motor or air is cut off.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an apparatus for controlling cooling of a linear motor including: a stator having a first temperature sensor, a heat sink and at least one cooling fan installed at a predetermined portion thereof; a mover having a second temperature sensor and a heat sink installed at the upper surface thereof; an encoder for sensing a position of the mover and generating a position signal; an A/D converter for receiving and converting signals from the first and the second temperature sensors and outputting a first and a second temperature sensing signals; a controller for generating a plurality of cooling fan control signals and an air valve control signal to cool the heat generated from the stator and the mover; a D/A converter for converting the plurality of cooling fan control signals and the air valve control signal and transmitting a plurality of drive signals to the plurality of cooling fans and to the air valve; and a mover driver for providing a drive signal to a coil block.
To achieve the above objects, there is also provided a method for controlling cooling of a linear motor including the steps of: operating a mover in a predetermined direction (S11); measuring temperatures (Ts, Tm) of a stator and the mover by using a first and a second temperature sensors respectively installed at the stator and the mover (S12); comparing the temperature values (Ts, Tm) with a pre-set reference temperature (a comparative value) (S13); computing a temperature value difference in case that the temperature values (Ts, Tm) are greater than the comparative value (S14); computing the computed temperature as a temperature gain (S15); and controlling a first and a second cooling fans and an air valve 33 according to the temperature gain by the controller.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.